Manufacturing method of flux gate sensor

Abstract

A manufacturing method of a flux gate sensor may include: a first step of forming a first wiring layer on a substrate; a second step of forming a first insulating layer to cover the first wiring layer; a third step of forming a magnetic layer on the first insulating layer, the magnetic layer constituting a core of a flux gate; a fourth step of forming a second insulating layer on the first insulating layer to cover the magnetic layer; and a fifth step of forming a second wiring layer on the second insulating layer. The first wiring layer and the second wiring layer may be electrically connected to each other so that each constitutes a magnetic coil and a pickup coil, and at least a process temperature in each of the third, fourth, and fifth steps may be lower than a glass transition temperature of the first resin.

1 . A manufacturing method of a flux gate sensor comprising at least:
 a first step of forming a first wiring layer on a substrate;   a second step of forming a first insulating layer made of a first resin to cover the first wiring layer;   a third step of forming a magnetic layer on the first insulating layer, the magnetic layer constituting a core of a flux gate;   a fourth step of forming a second insulating layer made of a second resin on the first insulating layer to cover the magnetic layer; and   a fifth step of forming a second wiring layer on the second insulating layer,   wherein the first wiring layer and the second wiring layer are electrically connected to each other so that each of the first wiring layer and the second wiring layer constitutes a magnetic coil and a pickup coil, and   at least a process temperature in each of the third, fourth, and fifth steps is lower than a glass transition temperature of the first resin.   
     
     
         2 . The manufacturing method of a flux gate sensor according to  claim 1 , wherein the glass transition temperature of the first resin is higher than 300° C. 
     
     
         3 . The manufacturing method of a flux gate sensor according to  claim 1 , wherein a temperature of the process in the third step is a higher temperature of a first temperature at a time of formation of the magnetic layer and a second temperature at a time of a heat treatment in a magnetic field which is performed after the magnetic layer is formed. 
     
     
         4 . The manufacturing method of a flux gate sensor according to  claim 2 , wherein the third step includes a first process of forming a cobalt-based soft magnetic film by a sputtering method, and a second process of performing the heat treatment in the magnetic field and controlling induced magnetic anisotropy in the formed magnetic layer. 
     
     
         5 . The manufacturing method of a flux gate sensor according to  claim 1 , wherein the first and second resins are the same photosensitive polyimide, a heat curing temperature of the first resin is 350° C. to 400° C., and a heat curing temperature of the second resin is 250° C. to 300° C. 
     
     
         6 . The manufacturing method of a flux gate sensor according to  claim 2 , wherein the first and second resins are the same photosensitive polyimide, a heat curing temperature of the first resin is 350° C. to 400° C., and a heat curing temperature of the second resin is 250° C. to 300° C. 
     
     
         7 . The manufacturing method of a flux gate sensor according to  claim 3 , wherein the first and second resins are the same photosensitive polyimide, a heat curing temperature of the first resin is 350° C. to 400° C., and a heat curing temperature of the second resin is 250° C. to 300° C. 
     
     
         8 . The manufacturing method of a flux gate sensor according to  claim 4 , wherein the first and second resins are the same photosensitive polyimide, a heat curing temperature of the first resin is 350° C. to 400° C., and a heat curing temperature of the second resin is 250° C. to 300° C.